1. Field of the Invention
The present invention relates to a fuel tank in which at least a part of a fuel storing unit is formed of a flexible film.
2. Description of the Related Art
Japanese Patent Unexamined Publication JP-A-2001-310644 discloses such a fuel tank having an elastic bladder film for storing fuel and a fuel pump apparatus including a liquid-level gauge. The bladder film and the fuel pump apparatus are arranged apart from each other inside the fuel tank. The fuel inside the bladder film is pumped up by the fuel pump apparatus and supplied to an engine.
Further, Japanese Unexamined Patent Publication No. JP-A-8-197969 discloses a fuel tank housing container having therein a fuel tank which is partially defined by an elastic film. Further, the fuel tank housing container has a separate chamber area located outside the fuel tank. The separate chamber area is provided with a fuel pump, the fuel pump supplying fuel inside the fuel tank to an engine.
However, in the fuel tank disclosed as above, since the fuel pump apparatus or the fuel pump is arranged outside the bladder film or the fuel tank defined by the elastic film, there is a problem that the structure is complicated and the number of components increases.
Therefore, arranging a fuel pump and a liquid-level gauge within a fuel storing unit formed at least partially of a flexible film to simplify the structure can be proposed. However, in this case, when the fuel storing unit expands or contracts according to an increase or a decrease of the storing amount of fuel, there is a possibility that the fuel storing unit and the fuel pump or the liquid-level gauge inside the fuel storing unit interfere with each other, thereby obstructing their functions.